Astronomy
Astronomy is the science that studies about celestial bodies and space. It applies math, physics and chemistry to explain the origin of these objects. The Astronomy includes the study of planets, stars, moons, galaxies and comets. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history performed observations of the night sky. It has included disciplines as astrometry, celestial navigation, astrophysics, observational astronomy and the making from calendars. History In the ancient times, astronomy only comprised the observations from the celestial bodies visible to the naked eye. At some locations, early cultures assembled artifacts that had astronomical purpose. In addition, these observatories could be employed to determine the year's seasons, an important factor in knowning when to plant the crops. During the Middle Age, the astronomy was mostly stagnant in medieval Europe at least in the 13th century. However, astronomy flourished at the Islamic world and other locations. This led to the emergence from the early astronomical observatories in the Mulism world at the 9th century. During the Renaissance Age, Nicolaus Copernicus made a heliocentric model that makes a reference to the Solar System, called as The Copernican System. Galileo Galilei and Johannes Kepler defended and expanded Nicolaus' idea. All of this happened somewhere in the 17th century, possibly. Stars Stars are astronomical bodies consisting from a luminous spheroid of plasma held together by its gravity. The nearest and most known star is the Sun, a giant burning ball made of hot plasma. However, other stars are also visible to the naked eye from Earth during the night. PSR B0943+10 is currently the smallest star known while UY Scuti is the largest star known. Planets Planets are astronomical bodies that usually orbit a star. The planets consist of internal structure and layers, with the most common layers being the crust, mantle and core. The most known planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, which form the Solar System along the Sun. Planets that aren't found in the Solar System are called exoplanets. Natural satellites Natural satellites, also known as moons, are astronomical bodies that orbit at the planet they belong to. These bodies are obviously smaller than the planets they orbit, and often serve for water and nighttime. There are also artificial satellites, which orbit like natural satellites, but however, they are made by humans. Asteroids Asteroids are minor planets and rocks that come from the space. However, when asteroids are large, they are called planetoids. Asteroids are confused with meteoroids and comets, but however, the three are different astronomical bodies. Vesta is so far the only asteroid discovered with a reflective surface. Asteroids can be found in the Solar System's asteroid belt. Astronomical bodies Astronomical bodies, also known as astronomical objects and celestial bodies, are natural entities that exist in the universe and are commonly composed of a structure named as; internal structure, which is commonly composed of the core. Examples of the celestial bodies are planetary systems, clusters and galaxies, with the stars, planets, moons and asteroids being the astronomical bodies. Astronomical bodies are commonly circular and spherical in shape, but other shapes like ellipsoids are applied mostly to the asteroids, moons and dwarf planets. Stars and planets are commonly spherical in shape and, so far, there are not ellipsoid-shaped types of this astronomical bodies. Planets can have rings, which are mostly made of rocks and ice. An example of planets having rings are the 4 outer planets; Jupiter, Saturn, Uranus, Neptune, with the second former and first latter having large rings that are easy to see from telescopes. Gallery File:Space.png|A field of stars at the outer space. File:Blue.jpg|Image featuring stars, but however, this time they are glowing blue. File:Solar.jpg|The Solar System, the planetary system where our home planet, Earth, can be found. Trivia *Currently, Jupiter has the title of the highest number of natural satellites, with 79 moons. *According to the future predictions, the Sun will turn into a red giant. **When it finishes this stage, it will start to pull the inner planets into it and probably the asteroid belt. **Although the outer planets might be temporarily safe, the Sun will explode and burn the outer region instantly. **At the present, it is currently in the half of this process. *Pluto was originally a planet. **However, due to being smaller than some moons but since Pluto contains moons, a classification of planet was invented. **This planet type is named dwarf planet. Category:Astronomy